1. Field of the Invention
The present invention relates generally to the administration of drugs and drug therapy and more particularly to the introduction of drugs into the lungs.
2. Description of the Prior Art
Several recent therapeutic developments entail the administration of drugs directly into the lungs. These include, for example, 1) the introduction of altered adenovirus in the "gene therapy" treatment of cystic fibrosis, 2) the use of surfactant in the treatment of pediatric and adult respiratory distress syndrome (ARDS), and 3) the introduction of antibiotics, antibodies, and other drugs.
Patients requiting the administration of drugs to the lungs face limited options. The most common approach, that of introducing a large liquid bolus directly into an endotracheal tube with a syringe, entails a number of drawbacks:
To optimize the uniformity of distribution of the bolus, the patient must often be rotated, PA0 The large liquid load can lead to severe respiratory complications, and PA0 The large amount of material required can lead to considerable expense. PA0 The efficiency of delivery is very low; only about 2% of the material introduced into the nebulizer actually remains in the lungs, PA0 Many drugs cannot be nebulized effectively, PA0 Achievement of a uniform distribution of material in the lungs remains problematic, and PA0 The protocol for use of the nebulizer is relatively complex. PA0 capable of delivering a spray of fine particles for deep penetration and broad distribution in the lungs, PA0 small and flexible enough to be inserted into an endotracheal tube, endoscope, or other intratracheal device, or directly into the trachea so as to minimize losses of drug material to the mouth, throat and trachea, PA0 of the liquid-pressure type of sprayer so as to avoid those problems associated with the common air-pressure type of sprayer, particularly the unwanted generation of a large mount of vehicle gas which may be injurious to the lungs.
A recent experimental approach is that of introducing ultrasonically nebulized material to the endotracheal tube via a "T" connection. While much lower amounts of such nebulized material have been found effective for treatment, this technique also has serious drawbacks:
These considerations point to the desirability of a device for delivering drug solutions directly into the lungs. In particular, such a device would be:
The present invention has been developed in view of the foregoing and to overcome the deficiencies of the prior art.